exposed emulsion rinse out...?

so i left this girl a screen with some exposed photo emulsion still on it. its probably been on the screen for 3+ months. im pretty confident that the screen is just fine and the emulsion would rinse out without much difficulty with the pressure washer (especially because its only a 150 count).

she refuses to believe this.. and because im 4 hours away from the studio i cant just do it myself. i thought maybe i would get some better advice before i tried to convince her further though.